Generally, an instrument panel is installed in the front of a cab of a work vehicle such as a shovel or a dump truck. Mounted on the instrument panel are many devices and components such as a meter panel that has meters and suchlike thereon, a liquid crystal monitor that displays images of the surroundings of the vehicle, a car stereo (including a radio), a navigation system, and a glove box. In the instrument panel, HVAC air blower outlets with grills attached thereto are formed in the cab side surface and, in addition, defroster air blower outlets are formed in the upper face, etc., located below and opposite windshield. These air blower outlets are connected to corresponding HVAC (Heating, Ventilating, Air Conditioning) and defroster ducts (hereinafter simply referred to as “HVAC ducts and suchlike”).
The instrument panel is formed as described below in order to securely withstand vibration so as to prevent comparatively heavy devices (e.g., a liquid crystal monitor, car stereo or navigation system) installed in such an instrument panel in a work vehicle from becoming detached or falling when the instrument panel is subjected to heavy vibration or heavy impact load during the operation of the work vehicle.
First, into the frame of a work vehicle a framework for an instrument panel is formed by sheet metal working. Heavy devices and suchlike are directly mounted in the framework, and HVAC ducts and suchlike are also fitted in the framework. Subsequently, the HVAC ducts and suchlike are connected to a cover molded from a synthetic resin. Then, the synthetic resin cover is fitted over the framework and thus the instrument panel is formed. Accordingly, even if the heavy devices and suchlike are subjected to a large vibration acceleration (about 7 G at the maximum) during the operation of the work vehicle, the heavy devices and suchlike are prevented from sliding by their own momentum or, consequently, becoming detached from mounted position or falling.
On the other hand, an instrument panel installed in the cab of an ordinary vehicle is less likely to be subjected to strong vibration or impact unlike a work vehicle as described above. Instead, an ordinary vehicle generally demands excellence and a high degree of freedom in design. Accordingly, unlike the above-described instrument panel for a work vehicle, an instrument panel for an ordinary vehicle is formed as described below. First, a synthetic resin is molded into a predetermined shape and its surface is integrally covered with a skin material, thereby forming the instrument panel. Then, various devices such as a meter panel are mounted in the thus obtained synthetic resin instrument panel, thereby composing a module. This module is mounted in a vehicle body frame such that an instrument panel with the various devices mounted therein is installed in front of a driver's seat in a cab.
A specific example of such an instrument panel used in an ordinary vehicle or suchlike is disclosed in, for example, Japanese Patent Laid-Open Application No. 2005-75089 (Patent document 1). In the instrument panel described in this patent document 1, a module is constructed by installing a meter panel, glove box, etc., into the instrument panel formed by molding a synthetic resin. Next, this module is mounted in a vehicle body frame via a reinforcement bracket and connected to HVAC ducts and defroster ducts. In the patent document 1, after the module is mounted in a vehicle body frame, a car stereo, and so on are mounted in predetermined places in the instrument panel. However, heavy devices such as a car stereo may be mounted in an instrument panel body together with the meter panel during the configuration of the module.    Patent document 1: Japanese Patent Laid-Open Application No. 2005-75089